Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B20623-1 found under Pinion And Gear Assembly by S S Precision Gear And Instr. The National Stock Number assigned to this part is 6680006736906, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B20623-1.